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Look at the blue Earth. This is our home. There are plains (平原), mountains, rivers, lakes and oceans (海洋) in our home. There are many kinds of trees, flowers, sand and grass in our home. There are many kinds of wild (野生)animals living together with us. But sometimes we do so many bad things to it. We waste too much water. We cut down too many trees. We hunt (捕猎) for too many wild animals for food or clothes. We waste too much energy (能源). Too many cars use a lot of energy. We use too many plastic bags. We shouldn’t do these things. We should save our Earth, because we have only one Earth.
1．There are no trees and grass on the Earth.2．There are many kinds of wild animals on the Earth.
3．We sometimes do so many bad things to destroy the Earth.
4．We don’t waste water.
5．We should save our Earth, because we have only one Earth.
同类型试题
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
